如何在多线程环境Java中关闭线程

Question

因此，我的服务器应用程序导致大量的CPU使用率，平均约为95％。 我认为原因是它不断产生新线程但没有关闭它。 当发生以下任何一种情况时，我应该如何关闭线程：刷新页面，注销，浏览器关闭。

对于服务器部分，我的代码或多或少像这样。

ThreadedEchoServer.java

public class ThreadedEchoServer {
    // using port 2000
    static final int PORT = 2000;

    public static void main(String args[]) {
        ServerSocket serverSocket = null;
        Socket socket = null;

        try {
            serverSocket = new ServerSocket(PORT);
        } catch (IOException e) {
            e.printStackTrace();

        }
        while (true) {
            try {
                socket = serverSocket.accept();
            } catch (IOException e) {
                System.out.println("I/O error: " + e);
            }

            // new thread for a client
            new EchoThread(socket).start();
        }
    }
}

EchoThread.java

/*
Class for java server to accept incoming stream
and create a new thread to save log file data in server
*/
public class EchoThread extends Thread {
    protected Socket socket;

    public EchoThread(Socket clientSocket) {
        this.socket = clientSocket;
    }

    public void run() {
        /*Create a File*/
        int i = 1;
        try {
            File directory = new File("F:/temp/tmplog/" + getDate());
            if(!directory.exists()) {
                directory.mkdir();
            }

            String fileName = "F:/temp/tmplog/" + getDate() + "/" + getDateTime() + ".txt";
            File file = new File(fileName);

            //Double Make Sure it create the file
            while(file.exists()) {
                file = new File(fileName + "." + i);
                i++;
            }
            FileOutputStream fis = new FileOutputStream(file, true);
            PrintStream out = new PrintStream(fis);
            System.setOut(out);


            while (true) {
              try {
                InputStream is = socket.getInputStream();
                BufferedReader br = new BufferedReader(new InputStreamReader(is, "US-ASCII"));

                String line = null;

                while ((line = br.readLine()) != null) {
                  System.out.println(line);
                }
              } catch (IOException exception) {
                // Just handle next request.
              } finally {
                if (socket != null) {
                  try {
                    socket.close();
                  } catch (IOException ignored) {
                  }
                }
                fis.close();
              }
            }


        } catch (IOException ignored) {
        }
    }

该服务器应用程序基本上将为每个线程/客户端打开一个新文件并写入一个日志文件。 我认为问题是使用后我不关闭线程。 这就是为什么它不断产生新线程的原因。有帮助吗？

Answer 1

如果我了解您要查找的内容，则可以使用超时来处理这种情况。 超时到期后，您将终止线程。

回声线程

/*
Class for java server to accept incoming stream
and create a new thread to save log file data in server
*/
public class EchoThread extends Thread {
    protected Socket socket;

    public EchoThread(Socket clientSocket) {
        this.socket = clientSocket;
        this.socket.setSoTimeout(10000); //Sets timeout to 10 seconds
    }

    public void run() {
        /*Create a File*/
        int i = 1;
        try {
            File directory = new File("F:/temp/tmplog/" + getDate());
            if(!directory.exists()) {
                directory.mkdir();
            }

            String fileName = "F:/temp/tmplog/" + getDate() + "/" + getDateTime() + ".txt";
            File file = new File(fileName);

            //Double Make Sure it create the file
            while(file.exists()) {
                file = new File(fileName + "." + i);
                i++;
            }
            FileOutputStream fis = new FileOutputStream(file, true);
            PrintStream out = new PrintStream(fis);
            System.setOut(out);


            while (true) {
              try {
                InputStream is = socket.getInputStream();
                BufferedReader br = new BufferedReader(new InputStreamReader(is, "US-ASCII"));

                String line = null;

                while ((line = br.readLine()) != null) {
                  System.out.println(line);
                }
              } catch (IOException exception) {
                // Just handle next request.
              } finally {
                if (socket != null) {
                  try {
                    socket.close();
                  } catch (IOException ignored) {
                  }
                }
                fis.close();
              }
            }


        } catch (IOException ignored) {
        } catch (SocketException e) { //Exception thrown by timeout
            socket.close(); //We close the socket
            this.stop(); //We stop the thread
        }
    }